﻿//
//  Monkey Manager
//  Copyright (C) 2011 Victor Tereschenko (aka sibvic)
//
//  This program is free software: you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  (at your option) any later version.
//
//  This program is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
//     
// ========================================================================

using System;
using System.Collections.Generic;
using System.Collections.Concurrent;
using System.Linq;
using System.Text;
using System.Threading;

namespace Sibvic.Command
{
    /// <summary>
    /// Executes commands from queue.
    /// </summary>
    class CommandEngine : IDisposable
    {
        public CommandEngine(ConcurrentQueue<ICommand> queue)
        {
            mCommands = queue;

            mWorker = new Thread(new ThreadStart(theJob));
            mWorker.Start();
        }

        public void ResumeProcessing()
        {
            mStartProcessingEvent.Set();
        }

        void theJob()
        {
            while (true)
            {
                mStartProcessingEvent.WaitOne();
                executeAllCommands();
                mStartProcessingEvent.Reset();
            }
        }

        private void executeAllCommands()
        {
            while (true)
            {
                ICommand command;
                if (!mCommands.TryDequeue(out command))
                    return;

                try
                {
                    command.Execute();
                }
                catch { }
            }
        }


        ConcurrentQueue<ICommand> mCommands;
        Thread mWorker;
        ManualResetEvent mStartProcessingEvent = new ManualResetEvent(true);

        bool mDisposing = false;
        public void Dispose()
        {
            if (mDisposing)
                return;
            mDisposing = true;
            mWorker.Abort();
        }
    }
}
